Jan, I'm really glad you have brought this topic up again. I have been looking for O'Brien's yuloh piece for ages, but confess that I did think it contained rather more information.
Of course I no longer have access to a workshop and, to be honest, I'm not quite sure if I could actually fit a working yuloh on FanShi, but I'd dearly love to have one. At least 50% of the time when I start my engine, a yuloh would have done the job and I hate the noise from the motor. Anyway, I've now bookmarked this thread so hopefully, I can find it again.
Edit: When I was in the Falkland Islands, Ilen was still there - she was built to go there as a working boat - and still being used. I was so pleased to read about her restoration several years ago.